Mechanical motion transmitting device



Jan.'18, 1938. F. scl-laEL El AL MECHANICAL MpTIos- TRANSMITTING DEVICE Filbd- March 3, 1937 Inventor's z 4 Fritz Schbel,

Their" Attorney.

Patented Jan. 18, 1938 UNITED STATES PATENT OFFHE MECHANICAL MOTION TRANSMITTING DEVICE York Application March 3, 1937, Serial No. 128,842 In Germany March 10, 1936 Claims.

Our invention relates to mechanical motion transmitting devices, and more particularly to motion transmitting devices of the slotted crank type.

One object of our invention is to provide an improved slotted crank capable of moving into each of two extreme positions with a snap action.

Another object of our invention is to provide improved operating mechanisms for valves used in gas meters.

Our invention will be better understood, and other and further objects of our invention will be apparent by reference to the following description when taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

In the .accompanying drawing, Fig. 1 discloses in perspective, a front elevation of our improved motion transmitting device as applied to a gas 20 meter, and Fig. 2 is an end view partly in cross section of the operating arm, or crank, illustrated in its two extreme positions.

Referring to the drawing in detail, Fig. 1 illustrates a valve housing 5 of a gas meter such as is 25 disclosed in U. S. Patent 1,878,344 issued September 20, 1932, divided by a wall 6 into two chambers 'I and 8, each of which contains an opening controlled by a valve. The valves 9 and II], respectively, controlling these openings, are

arranged in such manner that when one of the auxiliary chambers is closed, the other is opened.

In Fig. 1, the valve 9 is illustrated as being open,

and the valve In is shown as being closed, their respective stems II and I2 being arranged to 35 move horizontally, in any suitable guides (not shown), are connected by a crossrod I3, upon which is mounted a spool I4. The spool I4 is loosely mounted on the cross rod I3, and is engaged by our improved device.

40 The motion transmitting device built in accordance with our invention comprises a crank I5 mounted at one end on an operating shaft I6, and provided at the other end with a pair of parallel rods I1 and I8 extending at right angles to the 45 crank I5 and upwardly between the flanges, and on opposite sides of the body of the spool I4. The parallel rods I1 and I8 are preferably made of a single length of metal wire, preferably of such metal as bronze or spring steel, bent into the 50 shape of a hair-pin and supported at the apex by a collar I9 formed at the end of the crank I5 by ears 2D and 2| which are bent about the rods I1 and I8 to rigidly hold them in position. A

kink 22 in the rod II near the apex enables the ear 20 to better grip the rod 11. The rod I8 is.

straight, and rod I1 is provided with a second kink 23 near its upper end, projecting inwardly, and providing a short narrowed space between the rods I! and I8. The operating crank being mounted upon the shaft I6, moves the parallel rods I1 and I8 in an arcuate path, thereby producing a horizontal movement of the spool I4 and the valve mechanism connected thereto, and a vertical movement of the kink 23 relatively to the spool; the kink 23 being above the spool in one operating position of the valves and below the spool in the second operating position. The mechanism for turning the shaft I6 is not shown, since it forms no part of our present invention. Our improved device is, however, specially adapted for use in gas meters of the type disclosed in the above-mentioned Strelow patent, and the mechanism therein disclosed can be adapted to rotate the shaft I6. The position of the crank in the two operating, or end, positions is better illustrated in Fig. 2.

Referring to Fig. 2, the shaft I6, together with the operating crank I5 and the parallel rods I1 and I8, are shown in full lines in the same position as in Fig. 1. The second position of the rods I1 and I8 is shown in dotted lines. In this second position of the rods I1 and I8, the connecting rod I3 has been moved inwardly to close the valve 9 and to open the valve Ill. The kink 23 in the rod I1 is clearly visible in both positions, above and below the spool body I4. In order to move between these positions in response to the movement of the crank I5 and a rotation of the shaft I6, the rod I1 is bent back so that the apex of the kink may pass over the cylindrical surface of the spool body. Since both the rod I1 and the rod I8 are made of bronze, or spring steel, the force required to move the spool past the kink is distributed between the two arms I! and I8, and they are both bent outwardly, and both tend to return to their respective normal positions. Therefore, when the apex of the kink 23 passes over the cylindrical surface of the spool body, an unstable condition is created and the resiliency of the rods tends to force the spool above, or below the kink 23. This action necessitates a slightly greater torque at the beginning of a movement of the crank I5, but provides an additional force at the end of such movement which tends to drive the valves into their respective positions. In this manner, therefore, a simple over-center device is provided for moving the valves into either of the two extreme positions with a snap action, and thereby eliminating a chattering or fluttering of the valves during these operations. On the other hand, a positive force is required to initiate an operation thereof.

The above-described motion transmitting device, although described as applied to the valves and the operating shaft of a gas meter, compn'ses a simple and inexpensive, yet rugged overcenter device capable of application to other mechanisms.

What we claim as new and desire to secure by Letters Patent of the United States, is:

1. In a mechanical motion transmitting device, the combination of an operated member provided with a cylindrical surface and arranged to move in a straight line between two end positions, an operating member including a crank provided with a pair of resilient members adjacent opposite sides of said cylindrical surface and arranged to move transversely of said operated member during its linear movement, and a tapered projection on one of said resilient members arranged to move past said operated member during said transverse movement to force apart said spaced members thereby creating an unstable condition between the two end positions of said operated member.

2. In a mechanical motion transmitting device, the combination of an operating crank including a pair of spaced resilient members, an operated member between said spaced members provided with a spool extending substantially between said two resilient members, a tapered projection on one of said parallel spaced members and projecting towards the other of said members thereby providing a reduced spacing between said spaced members, and means for moving said crank whereby said operated member is moved linearly and said tapered projection is moved transversely of said spool an unstable condition being created until said projection has moved past said spool.

3. In a dry gas meter, the combination of a valve, an operating stem therefor operable in a straight line to open and close said valve and provided with a spool having its axis substantially at right angles to said stem, a crank for operating said valve comprising a pair of spaced parallel and resilient arms engaging said spool on opposite sides of its axis, and a tapered projection on one of said arms projecting toward the other of said arms, said spool being moved past said projection during each operating movement of said valve whereby an unstable condition exists in any position of said valve except the open and closed positions thereof.

4. In a dry gas meter, the combination of a set of valves, a pair of valve stems arranged to operate said valves to opened and closed positions respectively, a cross bar provided with a spool connecting said valve stems for simultaneous operation, a crank for moving said cross bar comprising a pair of spaced resilient arms engaging said spool on opposite sides of its axis,

a tapered projection on one of said arms projecting toward the other of said arms said projection being moved transversely of said spool during each operating movement of said crank whereby an unstable condition is created until said projection moves past the said spool and a snap action is obtained at the end of each movement tending to quickly seat the valves in either direction of movement.

5. In a mechanical motion transmitting device, the combination of an operated member arranged to move in a straight line and provided with a cylindrical surface, a slotted crank engaging said surface on opposite sides thereof, a tapered member projecting into said slot, resilient means for holding said member in the said slot, and means for turning said crank whereby said projecting member is moved transversely of said cylindrical surface and provides a snap-action at the end of the movement of the said operated member.

FRITZ scHCiBEL. PAUL SCHUBERT. 

